Expedition Summary: Deep Sea Biodiversity & Ancient Volcanoes near Johnston Atoll

Infographic summary of the expedition detailing 23 days at sea, 19,551 km2 of seafloor mapped, 13 successful ROV dives, 278 samples collected, 10 students sailed on the expedition, 62 scientists participated remotely, 35 live ship-to-shore interactions, over 1,250 ship-to-shore participants, over 298,000 highlight video views, over 599,000 live stream views
Ocean Exploration Trust

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Geographic Focus: US waters around Johnston Atoll, within the Pacific Remote Islands Marine National Monument

Main Operations: Remotely operated vehicle dives and seafloor mapping

Sponsor: NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute

Expedition Overview

From June 19-July 14, 2022, the Ocean Exploration Trust and partners conducted a telepresence-enabled expedition aboard E/V Nautilus to explore the deep-sea biology and geology inside the Johnston Unit of the Pacific Remote Islands Marine National Monument (PRIMNM). The expedition used the E/V Nautilusremotely operated vehicles (ROVs) and acoustic sonars to survey unexplored areas, and thereby provide a foundation of publicly-accessible data to stimulate further exploration, research, and management activities. In addition to ROV and mapping operations, the expedition deployed open-ocean buoys during transits. A total of 31 scientists, engineers, and students sailed on the expedition, who were supported by 62 professionals from 33 institutions that participated remotely via telepresence technology. Throughout the planning and execution of the mission, the team worked closely with NOAA, US Fish and Wildlife Service, Office of Hawaiian Affairs, and educators to co-develop culturally-relevant outreach and education experiences, particularly those targeting communities in Hawaiʻi and across the Pacific.

Mapping Highlights

Over 19,551 km2 of the seafloor were mapped, including 14,091 km2 inside the Johnston Unit of PRIMNM, and the remainder during transits. Seafloor mapping focused on filling multibeam gaps around seamounts towards the southwestern extent of the Johnston Unit of PRIMNM, as well as the Mid-Pacific Mountains towards the northern extent. Several seamounts and larger ridge features were mapped for the first time.

ROV Highlights

The expedition completed 13 successful ROV dives at depths ranging from 40 to 3,878 m. Dives explored a wide diversity of habitats and geological features, including the flanks of Johnston Atoll, as well as those of offshore seamounts and guyots. Noteworthy observations included recording basalt atop most guyots with basalt morphologies overlying limestones. This suggests that some guyots in the region experienced multiple, discrete phases of volcanism. Other noteworthy observations included the discovery of high-density and high-diversity communities, fossilized whale bones, and the first record of the seapen genus Solumbellula from the Pacific. Overall, hundreds of species were documented, including several potentially undescribed species, and several range extensions. A total of 278 samples (115 biological, 100 geological, and 63 eDNA water samples) were collected, a record for E/V Nautilus expeditions, which will support future studies on the deep-sea biodiversity, geological age, and volcanic history of the region.

Ocean Exploration Trust

Education, Outreach, and Public Engagement

Over the course of the expedition, live stream video feeds received close to 600,000 views and highlight videos garnered nearly 300,000 views. While at sea, the team created 23 new education products and hosted 35 live interactions (in either English or ‘Ōlelo Hawaiʻi) with schools and community events, reaching over 1,250 people spanning 14 US States and Canada. Three professional educators and ten university students participated in the expedition, gaining valuable at-sea experience. Early expedition results were featured in four major media stories that were picked up by over 40 national and international media outlets.

Broader Impacts

The Johnston Unit of PRIMNM has been identified as an exploration, science, and management priority by several government agencies, including NOAA Ocean Exploration. The expedition was planned and executed around government priorities to close knowledge gaps. Mapping and ROV operations were conducted in unexplored areas, thus contributing directly to the National Strategy for Mapping, Exploring, and Characterizing the United States Exclusive Economic Zone (NOMEC), Seabed 2030, and the UN Decade of Ocean Science for Sustainable Development. Expedition activities will also advance NOAA mission priorities, particularly in terms of understanding ocean changes, sharing that knowledge with others, and conserving marine ecosystems. This work also helped advance priorities on education, diversity, and inclusion by providing opportunities for underrepresented minority groups to participate in the expedition. Finally, the data collected on this mission is an essential precursor to future explorations of the region, which will undoubtedly lead to many more discoveries.

Data Access

Data and samples collected during the expedition, including video and environmental data collected on every ROV dive, physical samples, mapping data, oceanographic, and meteorological data, have been sent to publicly-available repositories for archiving. Links to the data repositories are provided below and direct data links will be posted once available. In the interim, expedition data is available upon request. Highlight images, videos, and educational materials are already publicly available via the expedition website.

Data Types


Navigation (ship and ROVs)

Rolling Deck to Repository, Marine Geoscience Data System

Seafloor mapping (multibeam and sub-bottom)

Rolling Deck to Repository, Marine Geoscience Data System

Photos (ROV and topside)

Marine Geoscience Data System

ROV video (full dive videos and highlights)

YouTube, Marine Geoscience Data System

Geological samples (rocks and push cores)

Marine Geological Samples Lab at the University of Rhode Island

Biological samples (whole specimens and tissue)

Harvard University’s Museum of Comparative Zoology

ROV documentation and observations (dive reports, event logs, chat logs)

Marine Geoscience Data System

Surface buoy data (waves, winds, currents, and temperature)

Sofar Ocean

Ship-sensor environmental data (CTD, O2, air temperature, sea surface temperature)

Rolling Deck to Repository, Marine Geoscience Data System


Thanks to the captain and crew of E/V Nautilus, the Nautilus Corps of Exploration, the Ocean Explorations Trust, and all that supported the expedition as scientists ashore. The expedition was conducted under Permit 12543-22002 authorized by the US Fish and Wildlife Service, and funded by NOAA Ocean Exploration via the Ocean Exploration Cooperative Institute.